O-lower alkyl-s-anisyl chloromethylphosphonodithioates



United States Patent 01 3,442,985 Patented May 6, 1969 3,442,985 O-LOWERALKYL-S-ANISYL CHLOROMETHYL- PHOSPHONODITHIOATES Ralph B. Fearing,Bardonia, N.Y., assignor to Stauifer Chemical Company, New York, N.Y., acorporation of Delaware No Drawing. Filed Oct. 13, 1965, Ser. No.495,721 Int. Cl. C07f 9/40; A01n 9/36 US. Cl. 260-951 Claims ABSTRACT OFTHE DISCLOSURE O-alkyl-S-anisyl chloromethylphosphonodithioatesrepresented by the general formula ClCH: 8

l S-QOCH.

wherein R is lower alkyl. The compounds are useful as pesticides, forexample, controlling insects and mites. Representative compounds areO-ethyl-S-(p-anisyl) chloromethylphosphonodithioate, O isopropyl S(p-anisyl) chloromethylphosphonodithioate, O-is0amyl-S-(p-anisyl)chloromethylphosphonodithioate and O n propyl-S-(panisyl)chloromethylphosphonodithioate.

The present invention is concerned with a novel group of O alkyl Sanisyl chloromethylphosphonodithioates, their method of preparation anduse as pesticides.

The novel pesticides may be represented by the gen eral formula whereinR is lower alkyl. The lower alkyl radicals which are suitable for R arethe straight and branched chain aliphatics having from 1 to 8 carbonsand include for example, methyl, ethyl, isopropyl, octyl, and the like.

The general process for preparing the novel pesticides of the inventionmay be illustrated by the following reaction:

ClCHa S CICH: S

wherein R is the same as defined hereinbefore.

Preparation of the novel anisyl chloromethylphosphonodithioates involvesreacting p-mercaptanisole with a chloromethylphosphonochloridothioate,preferably in the presence of an inert sol-vent such as benzene,toluene, acetone, butanone, and the like, and in the presence of ahydrogen halide acceptor such as sodium carbonate, triethylamine,pyridine, picoline, and the like. The reaction may be carried out attemperatures between 25 C. and 70 C., but 40 C. to 50 C. is preferred.The reaction is only mildly exothermic and thus the temperature may beeasily controlled.

The following examples illustrate specific pesticides of the inventionand their method of preparation, but should not be construed as limitingthe broader aspects of the invention.

Example 1 wmmxcronsflms-Q-oom 11.2 grams of p-mercaptoanisole (0.08 mol)and 15.8 grams of O-ethyl chloromethylphosphonochloridothioate (0.082mol) were dissolved in 40 cc. of benzene contained in a reactor flaskfitted with a thermometer and stirring rod. 8.3 grams of triethylamine(0.82 mol) were added dropwise to the mixture. A mildly exothermicreaction ensued so that an ice bath was necessary to maintain thetemperature of the mixture at 40 C. After about 30 minutes when theaddition was complete, the mixture was heated for two hours at 50 C. Thereactants were then washed in a separatory funnel, twice with water,once with a 5% solution of sodium carbonate, and twice again with water.The product was dried and concentrated by evaporation to yield 24 gramsof O-ethyl-S-(p-anisyl) chloromethylphosphonodithioate (.08 mol); havingan index of refraction N =1.5949 and analysis of 10.15% P, 20.9% S, and12.1% C1 as compared to 10.4% P, 21.6% S, and 11.97% Cl, theoretical.

The following specific compounds may be prepared in accordance with theprocedure shown in Example 1, in the yields indicated. Sample analysesand indices of refraction are included in the examples.

Example 2 O isopropyl S- (p-anisyl) chloromethylphosphonodithioate;yield=% of theory; having an index of refraction N =1.5865 and analysisof 9.8% P, 20% S, and 11.3% Cl, as compared to 9.97% P, 20.6% S, and11.4% C1, theoretical.

Example 3 It-05110) 01cm) ms s-Qoom O n propyl S-(p-anisyl)chloromethylphosphonodithioate; yield 93%; having an index of refractionN =1.5910 and analysis of 9.6% P, 19.8% S, and 11.2% C1, as compared to9.97% P, 20.6% S, and 11.4% C1, theoretical.

Example 4 uonmoncmomo CwHQP wQ-OQH,

O -isoamy1- S (p-anisyl) chloromethylphosphonodithioate; yield 83%;having an index of refraction N =L5713 and analysis of 8.5% P, 18.2% S,and 9.4% Cl, as compared to 9.15% P, 18.9% S, and 10.5% C1, theoretical.

Although the new chloromethylphosphonodithioates have been found to begenerally active as pesticides, their activity against the housefly(Musca domestica) and two-spotted mite (Tetranychus telarius), isunexpectedly high. Pesticidal activity for the anisylchloromethy1phosphonodithioates is shown in Table I wherein thepercentage kill among the pest species is reported for a specifiedquantity of candidate compound, expressed in micrograms g-herein termedthe bioassay test) or for a percentage concentration in aqueousdispersion (here inafter termed the screening test). A slanted line isused to separate the percentage kill for the pest species shown on theleft from the percentage concentration (screening) or total quantity(bioassay) shown on the right,

Insect species HousefiyMusca domestica Linn.)

American cockroach-Periplanetaamericana(Linn.)

Salt-marsh caterpillarEstigmene acrea(Drury) Spotted milkweedbugncopeltus fasciatus(Dallas) Mite species Two-spotted miteTetranychustelarius(Linn.)

TABLE Le-MO RTALITY OF REPRESENTATIVE SPECIES OF COMMON INSECT 0 RDERSAND MITES T. telarius Compound (example number, Post see supra) M.domestlca P. americana E. norm 0. faacialus Embryonic Nymphs Eggs In thescreening tests for the insect species of Table I, from ten totwenty-five insects were caged in cardboard mailing tubes 3% diameterand 2%" tall. The cages were supplied with cellophane bottoms and screentops. Food and water were supplied to each cage. Dispersions of the testcompounds were prepared by dissolving one half gram of the toxicmaterial in ml. of acetone. This solution was then diluted with watercontaining 0.0175% v./v. Sponto 221, an emulsifying agent, the amount ofwater being sufiicient to dilute the active ingredients to aconcentration of 0.1% or below. The test insects were then sprayed withthis dispersion. After twenty-four and seventy-two hours, counts weremade to determine living and dead insects.

Some of the compounds which showed high mortality on house flies in thescreening test were bioassayed on M. domestica. In this test, a knownquantity of the toxicant was placed in a confined area. The same cageswere employed as for the fly screening test. A weighed amount of thetoxicant was placed in pyrex petri dishes having a surface area of 18.8sq. centimeters along with 1 ml. of acetone. After the solvent wasevaporated by air-drying, a. cage containing groups of twenty-fivefemale flies, three to five days old, was placed over the residue.Counts of living and dead insects were made forty-eight hours afterinitiation of the test.

Compounds which had an LD50 value (i.e., 50% of test species killed) perconcentration of 50 g. or less on house flies, were selected for contactstomach screening on the salt-marsh caterpillar. Dock le'avesapproximately five inches long were dipped in aqueous suspensions of thetest materials for ten seconds. The leaves were then placed in one pintfood containers with the stems projecting through small holes in thebottoms into vials containing water. Five 8 to 10 day-old salt-marshlarvae were introduced and the containers were closed with a petri dishlid. Mortality readings were taken at twenty-four and seventytwo hours.The results are shown in Table I.

ing to the lower forms of life customarily controlled by chemical meansand excluding the higher animals, the vertebrates, for example, rodents,birds, and larger forms which are more commonly controlled by mechanicalmeans such as traps. It will be apparent to one skilled in the art thatthe toxic activity demonstrated hereinb'efore on various test species inindicative of activity with species and orders not specifically shown.

The foregoing description is given for clearness of understanding only,and no unnecessary limitations should be understood therefrom, asmodifications will be obvious to those skilled in the art.

I claim: 1. A compound having the formula 01cm schloromethylphosphonodi- References Cited UNITED STATES PATENTS 4/ 1966Lorenz 260l XR l/ 1968 Schrader 260961 XR CHARLES B. PARKER, PrimaryExaminer.

ANTON H. SU'ITO, Assistant Examiner.

US. Cl. X.R. 260-73; 424-214

